This invention relates to container opening tools for containers having frangible closures, popularly known as pop top cans.
In recent years container manufacturers have marketed various metal containers, particularly for beverages, incorporating a frangible closure in one end panel. Such containers are intended to be self-opening to eliminate the necessity of employing a separate opening tool.
Two general types of such containers have come into general use. The first type is that incorporating a tear-away closure panel which is adapted to be removed completely from the container. A ring tab lying flush with the surface of the container is connected to the closure panel by a rivet. To open the container the ring tab is tilted upwardly by inserting a finger under the free end of the tab. This results in the closure-attached end of the tab lifting the end of the closure panel to which it is attached to break the closure panel's seal with the container opening. Next a finger is inserted in the tab opening and the closure panel stripped away from the container opening by pulling the ring tab in a direction upward and away from the top of the container.
The second type has come into use mostly as a result of environmental concerns over the proliferation of used ring tabs with their attached closure panels littering picnic areas, playgrounds and other places where people congregate. This second type also includes a closure panel with a coacting tab which lies flush with the container surface. In this structure, however, the closure panel is adapted to be depressed into the container opening. Neither it nor the tab becomes detached from the container after use. The tab, which is usually rectangular without a central opening, is fastened by a rivet to the container surface adjacent one end of the closure panel with one of its ends overlapping the end of the closure panel to which it is adjacent. To open the container, as with the opening tab of the first type structure, a finger is inserted under the free end of the tab which is pivoted upwardly. As the free end of the tab rises, the end adjacent the closure panel pivots downwardly to abut the closure panel and to pivot it inwardly into the inside of the container to which it remains attached by a hinge formed by a small strip of metal.
While these opening structures were intended to eliminate the need for separate opening tools, these container opening structures have limitations rendering them significantly less useful than originally intended. In gripping the tab, whether of the first or second type, fingernails sometime break or are damaged producing pain and discomfort. The force required to pull the tear-away type closure off and the force required to pivot the tab of the inwardly pivoting closure type results in bruises and cuts in the fingers and thumbs. The two types of tabs occasionally break loose leaving their containers closed or partially opened. To open a container with a broken tab a traditional can opener, pliers, or some suitable gripping tool is required. In addition to the inconvenience this also can lead to cuts on the hands.
Even without breakage under normal circumstances the force required to open either type of container is substantial sometimes resulting in spillage and posing a barrier to use of the containers by those without sufficient strength.
These problems are an inherent and integral part of these type self-opening containers and are more acute among people who daily dispense the contents of such containers such as bartenders, waiters and waitresses, and others involved in serving of refreshments.